Found in Radio Electronics from the 90s, this thermometer uses an integrated circuit that is unusual today. The sensor is a thermistor or NTC.
This two-port monostable of the 4001 was suggested by an article in the April 1988 Radio...
We found this circuit in a documentation from the 70s. Semiconductors are from the era and can be...
This circuit is from 1992 documentation. The transistor can be a TIP42 with a good heat sink for...